(a) Field of the Invention
The present invention relates to a joining method, and more specifically, relates to a method for joining different kinds of plates that joins at least two plate members of which materials thereof are different from each other through laser welding.
(b) Description of the Related Art
Recently, demands for fuel consumption enhancement of a vehicle have been increasing, and thus aluminum, magnesium, and composite materials are being widely applied to vehicle body components instead of steel that was used for the sake of high strength and light body weight.
Because it is difficult to join different kinds of light-weight materials due to high electricity/heat conduction rates and excessive contamination of a welding electrode, mechanical joining methods such as a self-piercing rivet or clinching have been used. However, the mechanical joining method is expensive and is difficult, and the joining quality thereof is rough compared with a high level of welding.
When steel and light weight materials are used for a vehicle body, there is no adequate method except for the mechanical method, and production efficiency is deteriorated because a production line is separately prepared for joining of materials of different kinds, which is limited to a few parts of a vehicle body.
The description of the related art is for comprehension of a background of the present invention and may include contents other than the conventional art that is already known to a person of common skill in the art.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.